JP2003524789A - Bidirectional optical module for multi-channel applications - Google Patents

Abstract

SUMMARY OF THE INVENTION According to the invention, at least one transmitter and at least one receiver are combined in a transceiver unit (10) which is integrated in a common casing (100) and this common casing (100). ) Describes a compact module provided with at least one further transceiver unit of this type or at least one additional transmitter unit or additional receiver unit (20). In an advantageous embodiment of the invention, the transceiver unit (10) is implemented according to a bidirectional transceiver module, also referred to as a TO-BIDI module, described in DE-A 93 120 733.5. The additional transmitting or receiving unit is likewise realized in a TO structure. Accordingly, the present invention proposes a compact module that integrates a sub-assembly of a known BIDI module and a TO-BIDI module each having characteristics.

Description

Detailed Description of the Invention

The present invention relates to a transmitting / receiving module or a light transmitting / receiving module for bidirectional optical communication transmission and signal transmission according to the general concept of claim 1.

In the field of fiber optic communication or message transmission, there have been a total of two in the last few years.
It is the prior art to transmit at least one channel in each direction in the duplex or half-duplex mode. EP-A-0 432 314 describes, for example, a transceiver module for bidirectional optical communication and signal transmission, known as BIDI module. In this module, two active elements (sender and receiver) are hermetically sealed and encapsulated as separate elements in one common module casing. Inside the hollow space of the casing, a beam splitter and a lens coupling optic (lens coupling) are arranged and the casing has a fiber connection to a common optical waveguide fiber. Through the transmitter, the optical signal can be input coupled into the glass fiber to which it is coupled, while being simultaneously or temporally staggered to receive another optical signal from the same fiber. The separation of the two signals is done by a beam splitter. The beam splitter can also include a WDM (Wavelenth Division Multiplexing) filter. The filter can reflect certain wavelengths and pass other wavelengths.

If, in addition to one channel in each direction, another channel in at least one direction is to be transmitted, an external fiber splitter or an external WDM filter, for example in front of the module, is used. It can be incorporated into a supply glass fiber. But this is a relatively unrealistic solution. On the other hand, German Patent Application No. 93114859.7 proposes a so-called multi-channel transceiver module. In other words, here, at least one further transmitter and / or receiver and the lens coupling optics belonging to them and at least one further beam splitter are provided in the common casing of the conventional BIDI module described above. Has been.
In this case, one or more further transmitters and / or receivers can be used, in particular, the so-called TO (Transistor Outline) standard structure, as described, for example, in the German patent application No. 931207333.6. Is realized in the form of. However, this solution has the disadvantage that for two-way transmission of another channel it is necessary to incorporate two TO modules, a light-transmitting module and a light-receiving module, in a common casing. .

The object of the invention is therefore to provide a two-way optical communication and signal transmission, which is constructed in a space-saving manner and which can be expanded in the simplest possible manner for further bidirectional channels. It is to provide a transceiver module with multi-channel capability.

[0005]   This problem is solved by the configuration according to the characterizing part of claim 1.

The present invention, which will be described below based on exemplary embodiments, solves the above-mentioned problems in a compact module in which at least one light transmitter or transmitter and at least one light receiver or The receiver is connected to a transceiver unit or a transmitter / receiver unit which is incorporated in a common casing and in this common casing at least one further transceiver unit of this type or at least one
The solution is such that one transmitter unit or light transmitter unit or receiver unit or light receiver unit is provided.

In an advantageous embodiment of the invention, the transceiver unit is a bidirectional transceiver module, also referred to as a TO-BIDI module, described in German patent application DE 93120733.5. Has also been realized. Furthermore, it is advantageous if at least one transmitting unit or at least one receiving unit is realized as a TO module. Thus, the present invention is a compact module in which the known sub-assemblies of the BIDI module and TO module, each having its own characteristics, are integrated.

The multi-channel BIDI thus formed thus has, in addition to the usual bidirectional function of the two bidirectional channels, additionally one or more channels in each direction. It can be transmitted at the same time.

Therefore, a conventional BIDI module with two bidirectional channels, namely one transmit channel and one receive channel, supplements one TO transmit or receive module with one TO-BIDI having the same outer dimensions. This results in one module with 3 channels. If one TO transmission module is supplemented with one TO-BIDI, one transmission channel and one reception channel and a second reception channel are obtained. If one TO reception module is supplemented with one TO-BIDI, two transmission channels and one reception channel are obtained accordingly. In addition, a TO laser and a TO receiver are connected to the TO-
Filling with BIDI results in two transmit channels and two receive channels, ie four channels. This, of course, can be extended to modular devices with three TO components, resulting in five channels and six.
A module with two channels results. A corresponding extension to a larger number of channels is achieved by a corresponding additional T by an additional filter in the optical beam path.
This can be done by a corresponding extension of the modules which are simultaneously out-coupled to the O component. This is possible very simply optically, especially when the optical elements of the TO component are selected for collimated beams in the module. This allows the maximum number of possible channels to be twice as large as the number of TO-BIDIs combined, but rather than TO-BIDI a simple TO transmit or receive component is used. When it comes down, it becomes a little less.

Another important advantage of the device of the invention is that the optical channel separation is possible in different or same types of TO-BIDI and BIDI modules. For example, when a WDM filter is used for almost lossless separation of two wavelengths in a module, the separation in TO-BIDI can also be based on two different wavelengths, again by the WDM filter. With a 3 dB beam splitter, one wavelength can also be distributed in intensity to one receive channel and one transmit channel respectively.

This means that by using TO-BIDI as a TO component in multi-channel BIDI, a WDM with multiple discreet wavelengths (eg four or more wavelengths according to the ITU standard). system,
In a so-called HD-WDM system, it means in particular that each individual channel can be operated in both directions. This results in full bidirectional functionality in each WDM channel as compared to the previously customary multi-channel HD-WDM systems that operate only in one direction. This means that in the novel multi-channel WDM transmission in individual glass fibers, the device according to the invention doubles the transmission capacity of the fiber by bidirectional operation.

The device according to the invention is therefore expedient so that two bidirectional module types with different optical elements result in new module types with functional properties which are significantly superior to those of the individual module types. Be combined. That is, according to the device of the present invention, not only any multi-channel module can be manufactured, but also a unidirectional multi-channel HD-WDM transmission system can be operated fully bi-directionally. In this case, the required wavelength stabilization, for example by temperature stabilization, can be carried out by a corresponding temperature stabilization of the entire module, as described, for example, in German Patent Application No. 9314860.5.

[0013]   Next, the present invention will be described in detail with reference to the embodiments related to FIGS.

In that regard: FIG. 1 shows a basic embodiment of the invention, FIGS. 2a, 2b show another embodiment of the invention with three TO components, FIGS. 3a, 3b 3c shows another embodiment of the invention with five TO components, FIG. 4 shows another different embodiment with n TO-BIDIs, and FIG. 2 shows a transceiver unit in the form of BIDI.

FIG. 1 shows a basic embodiment of the present invention. Multi-channel BI
The basic structure of a DI consists of a common casing base 100, two sub-components 10 and 20, and a common SM (single mode) connecting fiber 0. The lens coupling optical element 110 for this common optical waveguide fiber 0 is arranged in the shape of a spherical lens near the end of the optical waveguide fiber 0. However, this lens can also be omitted if the entire coupling optics is realized accordingly. The sub-component 10 attached to the module axis is a transceiver unit. It contains one sender and one receiver. This transceiver unit may be, for example, the TO-BIDI module described above, ie a two-way transceiver unit made in the TO standard structure described above and described in German Patent Application No. 93120773.6. This unit has full bidirectional functionality for the receive channel A, eg 1480 nm and the transmit channel, eg 1300 nm. The sub-component 20 incorporated in the common casing 100 is a TO-PIN diode in the example shown, i.e. another component made in the TO standard structure also described above, for example tuned to a wavelength of 1550 nm. A diode receiver for receive channel B. 95 each
Perfect wavelength-selective channel separation with an efficiency higher than%, is provided for the other receive channels in the corresponding WDM in the beam axis contained in the beam splitter 22.
It is implemented according to conventional BIDI technology by means of filters. A blocking filter 21 can also be placed in front of the TO casing of the sub-component 20 to eliminate unwanted wavelengths.

Corresponding channel separations for the transmit channel and the receive channel A in subcomponent 10 are known, for example German patent application No. 93120773.6.
It can be realized in the TO-BIDI technology described in the specification.

The key elements of this structure will now be described again for a better understanding with reference to FIG. FIG. 5 shows a bidirectional transmitting / receiving module in the TO structure (TO-BIDI module). It can be used as sub-component 10. The transceiver module essentially consists of a laser chip 1 as a light transmitter, which has a lens-coupling optical element 6, a light receiver 8 and a beam splitter 9 arranged in the beam path in the middle. The beam splitter is at least partially surrounded by a casing 7. A light entrance / exit window 11 is attached to the casing with glass. Laser chip 1 is a common support 2
It is located in. This support is advantageously made of silicon and can be mounted as a submount, for example on the bottom plate 19 of the TO casing.
The laser chip 1 is arranged on a common support between the two support parts 3, 4. A mirror layer 5 is provided on the end faces of these support portions adjacent to the optical cavity surface of the laser chip 1 and is inclined at an angle of about 45 ° with respect to the cavity surface. , The coherent beam emitted from the laser chip 1 is directed as an divergent light beam upwards substantially perpendicular to the surface of the common support 2.
Is deflected to the lens-coupling optical element 6 arranged above. The two support parts 3, 4 are preferably made of glass and, like the support 2, made of silicon and have a trapezoidal cross-section. On at least one support part, in this case support part 3, a lens-coupling optical element 6 is arranged and fixed such that the beam emitted from the laser chip 1 impinges on it substantially perpendicularly.

The mirror layer 5 adjacent to the front surface of the laser chip 1 comprises a beam splitter 9. This beam splitter reflects the beam emitted from the laser chip 1 and passes the beam which is input from the outside via the lens coupling optical element 6. Below the beam splitter 9, a light receiver 8 or an optical coupling portion for the light receiver 8 is provided on the lower surface of the common support 2.

The beam splitter 9 forms an optical separating device for different or the same wavelengths. Separation greater than 95% can be achieved when the optical wavelengths for the transmit and receive branches are different, ie when the beam splitter operates wavelength selective. 50% for two branches at the same wavelength
The separation of or separate separation can be adjusted. In order to realize bidirectional transmission, the mirror layer 5 which is adjacent to the front surface of the laser chip 1 and which is applied to the support part 3 must have a filter layer as the beam splitter 9. There is only. This filter layer reflects the laser light of the wavelength emitted from the laser and transmits the light of another wavelength incident from the outside. For light with a wavelength greater than 1.1 μm, the silicon is transparent and is preferably on the underside of a common support 2, which is preferably made of silicon, on a suitable light receiver 8 or on the outside where the light exits. It suffices to attach a suitable optical coupling to the vessel.

This type of TO-BIDI module shown in FIG. 5 can be used as a transceiver unit or as a sub-component 10 of FIG. 1 in the transceiver module of the present invention. However, it is also possible to use, as the sub-component 10, any other possible configuration of the transceiver unit.

The reception channel B can be separated by the beam splitter 22 without wavelength selectivity. In this case, it would be advantageous to use a beam splitter of approximately 5 dB as the beam splitter 22 in the main beam path. The beam splitter splits about 30% into sub-components 20 and passes 60%. This 60% is then distributed to the TO-BIDI module 10, for example at 30 dB.

For the modular device of the invention shown in FIG. 1, this results in the following versatility for the first possible bidirectional operating conditions for the three transmission channels:
1a. ) When using three wavelengths (eg 1300 nm; 1480 nm; 1550 nm), each is> 95% efficient and 35 for individual channels.
Full duplex operation in 3 channels with channel separation greater than dB.

1b. ) In two receive channels (eg 1300 nm and 1550 nm) in one receive channel and one transmit channel with an efficiency of> 95% and a channel separation of> 50 dB for the receive channel (eg 1550 nm) respectively. Full-duplex operation and half-duplex operation for the respective second receive and transmit channels, each having an efficiency of, for example, about 50% (for example, at 1300 nm).

1c. ) Half-duplex operation for all 3 channels (eg 2 receive channels and 1 transmit channel) when using one wavelength (eg 1300 nm or 1550 nm), eg uniform on all channels with about 30% efficiency Can be distributed to each other or can be distributed in different relationships.

A second versatility of use or operability for the three channels is that the TO component located laterally of the module body is not a TO-PIN diode, but its emission characteristic is in the module optics. When it is a matched TO laser, it can be used in the device of the present invention. Various possibilities are 1a)
It can be derived from 1b) and 1c) according to the purpose.

Furthermore, a third versatility in use or operability for the four channels lies in the fact that the two TO components arranged in the module casing are (lateral and axial) TO-BIDI. It can be used in the device of the invention. In this case, each two double channels are separated by a beam splitter at the optical beam axis and a beam splitter at the TO-BIDI. The possibility of deformation is expanded in this case by one channel and can be derived in this case also according to the pattern described above. In this case, it should be emphasized that four channels (for example, 1280 nm; 1380 nm; 1480 nm;
The possibility of full-duplex transmission over 1560 nm).

2a and 2b, another embodiment of the device according to the invention with three TO components 10, 20 and 30 and one SM-connecting fiber 0 in a common module casing is illustrated. TO component 10 is TO-BIDI and 2
Two other TO components 20 and 30 are TO lasers and / or TO-PINs.
It is a diode or TO-BIDI. The additional beam splitter 32 allows at least a portion of the beam coming from the connecting fiber 0 to be in the TO component 30.
Is deflected in the direction of. This beam splitter can also omit the wavelength selective filter. Due to the versatility of operation and availability described with reference to FIG. 1, this results in 3 to 6 possible transmission channels.

In FIG. 2a the two sub-components 20 and 30 are TO receivers. Blocking filters 21 and 31 can be pre-connected to the TO casing of the two sub-components.

In FIG. 2b the two sub-components 10 and 30 are shown as TO-BIDI.

In FIGS. 3 a, 3 b, 3 c five TO components 10, 20, 30, 40 and 50 and one SM connecting fiber 0 per common module casing 100 are shown.
Another embodiment of the device of the present invention having is shown. The beam splitters 42 and 52 serve to at least partially deflect the beam in the direction of the sub-components 40 and 50. At least one of the TO components is a TO-BIDI, or a transmitter, receiver or any variation for the purpose of the TO-BIDI. That is, overall, a maximum of 10 bi-directional transmission channels will occur for a complete TO-BIDI implementation. The following variants have been found to be of particular importance in this construction: I) In the first variant, four TO receivers are arranged laterally and one T
O-BIDI is arranged in the axial direction. In this case, for example, an HDWDM filter can be tuned in the ITU raster to separate the four receive channels into a 1550 nm window and thus the module can receive four channels. The TO-BIDI is then axially arranged and can activate the monitoring channel in a window of 1300 nm or bidirectionally at 1480 nm (see FIG. 3a).

II) In the second variant, four TO transmitters are located laterally and one TO-BI
The DI is axially arranged as opposed to the case of I) as a corresponding HDWDM transmitter (see FIG. 3b).

III) In a third variant, four TO-BIDIs are arranged laterally and one TO-BIDI for the supervisory channel is arranged axially in the ITU raster as a fully bidirectional HDWDM multi-channel transceiver element. (See Figure 3c)
.

In FIG. 4, n to 2n channels, where n ≧ 2, are meaningful for n ≧ 2 channels by adding mutually different TO components, each with aligned optical elements. The expandability of the invention of a "bidirectional multi-channel module" with elements is shown. In this case, in particular, a beam collimated on the optical module axis is significant. According to the invention, the TO component is a TO-BIDI, T
It may be an O laser or a TO-PIN. Also in this case, various combinations can be realized from the above description.

It has proved to be particularly advantageous here that all TO components are TO-B.
It is a modification shown in FIG. 4 which is IDI. In this case, for example, the HDWDM channel allocation may be all 2 according to the ITU standard of eg 8 or more channels.
It can be performed in heavy or half-duplex operation.

[Brief description of drawings]

[Figure 1]   1 is a schematic diagram of a basic embodiment of the present invention.

Figure 2a   FIG. 6 is a schematic diagram of another embodiment of the present invention having three TO components.

Figure 2b   FIG. 6 is a schematic diagram of another embodiment of the present invention having three TO components.

FIG. 3a   FIG. 6 is a schematic diagram of another embodiment of the present invention having five TO components.

FIG. 3b   FIG. 6 is a schematic diagram of another embodiment of the present invention having five TO components.

[Fig. 3c]   FIG. 6 is a schematic diagram of another embodiment of the present invention having five TO components.

[Figure 4]   FIG. 6 is a schematic diagram of another various different embodiments having n TO-BIDIs.

[Figure 5]   FIG. 3 is a schematic diagram of a transceiver unit in the form of TO-BIDI.

[Explanation of symbols]

0 connection fiber, 1 laser chip, 2 support member, 3 support member,
4 support member, 5 mirror layer, 6 lens coupling optical element, 7 casing cap, 9 beam splitter, 10 transmission / reception unit, 11 light entrance and exit window, 19 casing bottom, 20 second sub-component, 21 blocking filter, 21 22 Beam Splitter, 30 Third Sub-Component, 31 Blocking Filter, 32 Beam Splitter, 40 Fourth Sub-Component, 41 Blocking Filter, 42 Beam Splitter, 50 Fifth
Subcomponents of, 51 Blocking filter, 52 Beamsplitter, 100
Common casing base, 110 lens coupling optics, (n + 1) (n
+1) th sub-component, (n + 2) (n + 2) th sub-component,
(2n + 1) (2n + 1) th sub-component, (n + 1) 2 (n + 1)
Second beam splitter, (n + 2) 2 (n + 2) second beam splitter, (2n + 1) 2 (2n + 1) second beam splitter

Claims (14)

[Claims] 1. A transceiver module for bidirectional optical communication and signal transmission, comprising at least one transmitter, at least one receiver and at least one fiber connection to an optical waveguide fiber (0). A part, a lens coupling optic and at least one beam splitter (22) intermediately arranged in the beam path, these being of the type arranged in a common casing (100), at least One transmitter (1) and at least one receiver (8) are coupled to a transceiver unit (10) incorporated in said common casing (100) and to said common casing (100), At least one other transmitting / receiving unit or at least one additional transmitting unit or additional receiving unit Transceiver module, characterized in that is provided. 2. The transceiver module according to claim 1, wherein the transceiver unit (10) is arranged on the axis of the optical waveguide fiber (0). 3. The transceiver module according to claim 1, wherein the beam splitter (22) includes a wavelength selection filter. 4. The transceiver module according to claim 1, wherein the beam splitter (5) included in the transceiver unit (10) includes a wavelength selection filter (9). 5. In the transceiver unit, a laser chip (1) is arranged on a common support (2) as a transmitter between at least one support part (3) of the support part, The side surface of the laser chip (1) adjacent to the cavity surface is provided with a mirror layer (5) and is inclined at an angle of about 45 ° with respect to the cavity surface, so that the laser chip ( The beam emitted from 1) is arranged substantially perpendicular to the surface of the common carrier (2), above the laser chip (1) and at least one carrier part (3, 4). The mirror surface (5), which is adapted to be orientated to the lens-coupled optical element (6) fixed to and is adjacent to the front surface of the laser chip (1), is a beam splitter (
9), which reflects the beam emitted from the laser chip (1) and allows the beam input from the outside through the lens coupling optics (6) to pass through and the beam splitter ( On the lower surface of the common support (2) below 9), the light receiver (
8) Or the transmission / reception module according to any one of claims 1 to 4, which is provided with an optical coupling portion for the light receiver. 6. Receiving unit (20) (FIG. 1) The transmission / reception module according to any one of claims 1 to 5. 7. Having a transmission unit The transmission / reception module according to any one of claims 1 to 5. 8. Having another transmitting / receiving unit The transmission / reception module according to any one of claims 1 to 5. 9. It has two receiving units (20, 30) (FIG. 2a). The transmission / reception module according to any one of claims 1 to 5. 10. A transceiver module according to claim 1, comprising one receiving unit (20) and one further transmitting / receiving unit (30) (FIG. 2b). 11. Transceiver module according to claim 1, comprising four receiving units (20, 30, 40, 50) (FIG. 3a). 12. Having four transmitter units (FIG. 3b). The transmission / reception module according to any one of claims 1 to 5. 13. It has four separate transceiver units (30) (FIG. 3c).
) The transmission / reception module according to any one of claims 1 to 5. 14. Having 2n separate transceiver units, where n ≧ 2.
The transmission / reception module according to any one of claims 1 to 5.